Gear finishing machine



' Jan. 20, 1942. R, s, DRUM QND 2,270,831

GEAR FINISHING MACHINE Filed April 5, 1937 9 Sheets-Sheet 1 I/ z, I E-25 f ,1: 6| B 23 a 23 I m y 21 2 Im 1 48 2| l l9 l4 f il l fl BA l6. 20l I 22 l 68 ll l 7 S 25 l g g INVENTOR BY ROBERT $.DRUMMOND MW /W+ATTORNEYS Jan. 20, 1942.

R. s. DRUMMOND GEAR FINISHING momma Filed April 5, 1'93? 9 Sheets-Sheet2 lnr falollll INVENTOR ROBERTSDRUMMOND Mi t ALM! W ATTORNEYS FIG; l4.

Jan. 20, 1942 s, DRUMMQND 2,270,831

GEAR FINISHING MACHINE Filed April 5, 1957 a l 9 Sheets-Sheet 3 VVENTORROBERT $.DRUMB D Y wW MM 43M.

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Jan. 20, 1942. R. s. DRUMMOND GEAR FINISHINF MACHINE Filed April 5, 19s?9 Sheets-Sheet 4 INVENTOR ROBERISDRLMMOND BY A TTORNEYS Jan. 20, 1942.R. s. DRUMMOND GEAR FINISHING MACHINE 9 Sheets-Sheet 5 Filed April 5,1937 gm lllllll ll j IN VE 1V T OR' ROBERT. 8. DRUMMOND A wlkm M,

A TTORNEYS Jan. 20, 1942. R. s. .DRUMMON D 2,270,831

GEAR FINISHING MACHINE Filed. April 5, 1937 9 Sheets-Sheet 6 IN VENTORROBERT S. DRU MMO ND BY m lWi-W A TTORNE YS Jan. 20, 1942. R. s.DRUMMOND GEAR FINISHING MACHINE Filed April 5, 19:57

9 Sheets-Sheet 7 He. l6.

7 INVENTOR ROBERT. s. DRUMMOND wilt, 1W +03% A TTORNE YS Jan. 20, 1942.R. s. DRUMMOND GEAR FINISHING MACHINE Filed April 5, 1937 9 Sheets-Sheet8 INVENTOR ROBERT. S. DRUMMOND.

[W ATM A ATTORNEYS Jan. 20, 1942. R: s. DRUMMOND GEAR FINISHING MACHINEFiled April 5, 1937 9 Sheets-Sheet 9 INVENTOR ROBERT. S. DRUMMOND.

I WW ATTORNEYS operations simultaneously I drive mechanism, thuseliminating mechanical 1 UNITED STATES PATENT oFFIcE GEAR FINISHINGMACHINE Robert s. Drummond, Detroit, Mich.

Application April 5, 1937, Serial No. 135,184

7 Claims.

\ The present invention relates togear finishing 4 and more particularlyto apparatus and-methods for simultaneously performing a plurality ofoperations on one or more gears. Specifically, the

, invention pertains to an application of the princlples described in myco-pending applications Serial No. 3,662, filed January 26,1935, andSetools having conjugate teeth intermeshing with the teeth of the'gearto be finished, the axes of the gear and tool being crossed at an anglevarying from 3 to 30.

.In each of the applications referred to, there are shown one gear andone cutter, the latter being driven and, because of its intermeshingrelation with the gear, thereby rotating the.work'piece. At the sametime a relatively reciprocating mo-. tion of the gear and tool iseffected, either by moving the gear back and forth with respect to thetool, or vice versa. It is understood of course,

with rotation of the gear and tool. The sides of the gear teeth arethuscut or shaved evenly and when finished have surfaces which are smoothand extremely accurate with regard to dimensions.

It has been found that it is possible and desirable under certaineircumstancesto perform a plurality of operations simultaneously on onegear by tools spaced from each other circumferentially with respecttothe gear. Certain roughing or primary finishing operations may, forinstance, be carried out on one portion of the gear immediately prior tothe final finishing operarial No. 52,566, filed December 2, 1935,wherein gears are finished by employing rotary cutting that thisreciprocation takes place co-inciclentally tion without necessitatingremoval of the gear from the finishing machine. Also, a plurality ofgears are frequently secured to or formed integral with a shaft orsleeve such, for instance, as

so-called cluster gears," and it is desirable to finish more than one ofthe gears simultaneously by suitably positioned tools acting on theseveral ears.

It is an object of this invention to provide a machine capable ofperforming a plurality of but with a single work and timingdifllculties, yet eifectively and accurately finishing a; gear or aplurality of gears.

- It is another object of the invention to provide separate andindependent means for effecting relative reciprocating motion betweenthe tools and the work gear or gears.

' It is also an object of the invention so to position the cutting toolscircumferentially with refor moving the tools quickly toward or awayfrom i engagement with the work after'said' initial setting. Otherobjects will be apparent from the following description taken with theaccompanying drawings, in which Fig. 1 is a perspective of a machineshowing a preferred arrangement and relation of the finishing tools anddriving mechanism;

Fig. 2 is a front view of one tool head and carriage, parts thereofbeing-broken away for clearness;

Fig. 3 is a side viewof the head and carriage shown in Fig. 2, certainparts thereof'being broken away and others being shown in section;

Fig. 4 is a front view, partly in section, of a clutch and gearingassociated with a tool for driving the same;

Fig. 5 is a detail of means for setting a tool angularly with respect tothe work;

Fig. 6 is a side view of themachine, the mechanism shown being thatemployed for separating the tools from the work;

Fig. 7 is a partial plan controlling certain motor switches in themachine;

Fig. 8 illustrates one means for actuating the mechanism shown in Fig.6;

Fig. 9 is a partial front elevation of the machine, certain partsthereof being omitted for clearness:

Fig. 10 is afragmentary view of one arrangement of the work gear andfinishing tools;

Fig. 11 is a fragmentary view of a roughing cutter showing the manner inwhich the cutting edges thereon are spaced;

Fig. 12 is a fragmentary view of a finishing cutter illustrating thespacing of the cutting edges;

Fig. 13 is a view similar to Fig. 10 but in which a cluster gear isbeing finished;

Fig. 14 is a diagram illustrating, the method of finishing a gear toothhaving a severe modification;

Fig. 15 is a diagrammatic view of roughing and finishing cutters forcarrying out the method of Fig. 14;

Fig. 16 is machine;

Fig. 1'1 is a sectional elevation of the workcarrying slide mechanism;

Fig. 18 is a sectional plan view of the mechanism shown in Figure 17; V

Fig. 19 is an end view of the parts shown in Fig. 18 with parts brokenaway;

Fig. 20 is an enlarged fragmentary side view of a portion of the drivemechanism shown in Fig. 16;

Fig. 21 is a section on line 2 l--2l of Fig. 17.,

As shown in Figs. 1 and 9, the machine consists of a frame or base llhaving a bearing II in which is journaled a spindlepr shaft li and aside view of a modified form of view of cam mechanism.

- a tailstock l4 provided with center I 5. It will 'the gear finishingoperations.

- 30 drives worm gear 3|.

has a driving flange I3B engaging the driving dog I3A on the clustergear l6.

Mounted on the frame for adjustment transversely with respect tothe axisof the work,

-' which in the type of machine illustrated, is a .vertical adjustment,are cutting tools I9 and 20. As shown in the drawings, these tools arePOSi-y tioned substantially diametrically opposite each other withrespect to the work gear, but it is within the invention broadly toposition them otherwise if so desired. Each of the tools is journaledina housing, the latter being indicated at 2i and 22, and the axes of thecutters are disposed at an angle to that of the shaft [13.

The tools are gear like and similar to those shown in the co-pendingapplications to which reference has previously been made herein. Bydriving the tool, the work is rotated by intermeshing engagement of theteeth on the tool and work gear. The tool housings are secured toreciprocable carriages 23, 24 respectively, and, as will be explainedhereinafter, are angularly adjustable thereon. These carriages aremounted in suitable ways- 5% (see Fig. 6) on heads 25, 25, the

ways being disposed parallel to the axis of the work. The heads-in turnare adjustably fixed on ways within the frame. Reciprocatingmechanismsdriven by motors 27!, 28, are connected to the carriages whereby thelatter are moved back and forth with respect to the work gear duringthat the reciprocating carriages and the driving -mechanisms thereforare independent of each other, and are adapted to be controlledseparate- 1y so that any desired relative movement of the It is to benoted with clutch member 42. This m1 is on the shaft 43 may be driventhrough gears 44, 4B, the

latter on shaft 43 and the former on splined shaft 46. A dental clutchmember 41 splined on shaft 46 is slidable into engagement with themember 42, its position being controlled by lever 48.

While it is preferred in many cases. to drive thework gear, it isapparent that, if desired, the finishing tool may be positively drivenby its own motor. The means for reciprocating carriage 24 and tool 20,and for driving the toolv from its motor are identical with. that fortool l9, and therefore requires no description. It has been previouslystated herein that the axes of the finishing tools cross the axis of thework gear and that means are provided for varying and setting theangular relation between these axes. In Figs. 3, 4 and 5, there is showna worm shaft 49 having abearing 50 in the tool housing, a worm 5| beingsecured to the end of the shaft, the-other. end of which is squared at52 to accommodate an adjusting handle. Worm 5i meshes with a toothedring '53 fast on carriage 23 and when rotated the worm turns the toolhousing about a vertical axis coincident with that of shaft 39 andpassing through the tool. In this manner the tool may be set at thedesired angle with respect to the axis of the work gear. After setting,suitable fastening means secure 'thetool in its adjusted position.

The means for adjusting the tool with relation to the work andseparating the tools to load or ways 60, along which and to which theheads carriages with respect to the work, either with regard to lengthof stroke or speed, is obtainable.

Furthermore, each tool housing is adjustable ang'ularly to vary therelative angle between the axes of each other and that of the work.

Certain details of the machine will now be described and explained. Aswill be seen from Fig. 2', the shaft 21A of the motor 2! is connectedtoshaft 30 by a coupling 213. A worm 29 on shaft i spaced and positignedon the frame ai'e adapted to reversethe direction of the motor atpredetermined intervals so that the carriage and finishns tool carriedthereby are moved back and forth in the direction of the gear axis. Itis to Gear 32 coaxial with be noted, however. that in addition to .itsreciprocating movement, each finishing tool is -rotated' either throughintermeshing engagement with'the work gear when the latter is driven, as

'by r'notor IT, or by clutch means connecting the 7 tool with the motor,in which case the gear is driven-from the tool. One manner of drivingthe finishing tool from the motor 21 is shown in Fi s. 2 and 4, whereinit will be seen that worm 31 on shaft 30 drives worm gear 38 on shafting. with a second bevel gear; 4| formed integral may be adjusted andfastened. The primary adjustment. of the heads and tools is effected byturning shaft ti. having a beveled gear 62 on the end thereof meshingwith a second bevel gear 62' on shaft 63. On the latter shaft is a wormtil meshing with worm wheel 65 having a keyed connection with thethreaded spindle 56. This spindle cooperates with nut 66' secured to theauxiliary slide and, since it is adjustable with respect to the head,-the position of the latter relative to the hanger may beiixed to cut thegear to the proper depth. The cams on the han er normally guide. thetool heads in such a way that the tools are in finishing relationto thework gear. Whenit is desired to separate the heads, the cams, each ofwhich is provided with opposed rises and dwells, are rotated to elevatethe upper head and drop the lower head. After the proper adjustment ismade between the cutter and the work, the auxiliary slide is clamped infixed relation to the head 25 by the eiamping screws 55A. For thepurpose of rotating the cams, a motor 61 is providedan'd itsoperatiorris dependent on movement of lever 68 at the front' of the machineReferring to Figs. 6,7 and 8,

it will be seen that by throwing the-le'verto one side, eccentric 69 andlink 18 rotate member 1i, carrying pawl 12. Ratchet l3 fastened on shaftI 14 is turned to rotate disk 15, also secured tosl 'aft 39. On thelatter shaft is a bevel gear 40 mesh! 14, an amount suflicient todisplace a dogliinto position to permit actuation of theswitch'll', the

latter closing the motor circuit. 'A second switch Where a roughing anda finishing cutter oper- (not shown) adjacent the from; of the machineand under control of the operator starts the motor. It'is to benoted-that clutch members 18,

1 19, forming an overrunning clutch, permit a connection between lever68 and shaft H but do not couple the motor 61 with shaft 14 in theinitial rotation of the shaft. Gears 80 and BI on shafts l4 and 82 andconnected by idler gear 83, permit the motor 61 to rotate cams 51, 58when the starting switch is closed and, as shown in Fig. 3, guide thetool carrying heads to feed the tools radially towards the gear. Afterthe cams have rotated sufliciently to make the desired cut on the gear,a second dog It on disk I5 stops themotor. When it is desired to againseparate the tools, the lever is again thrown to actuate the pawl andratchet mechanism. Disk 15 then completes its cycle and the motor isagain stopped. At this time the cams 51, 58 are again in that positionwhere the heads are separated. It is I to be noted that while the headsare separated.

the motors for rotating the work and tools are inactive. In order tobreak the tool actuating motorcircuits switch 84 actuated by a cam 85'on shaft I4 is thrown when the shaft is rotated 'mary finishing orroughing operation on the wcrk and the other a final finishingoperation. Furthermore, their respective angular positions with regardto the axis of the work, the rates of feed longitudinally of the workduring rotation of the gear, and in some cases, the diameters of thecutters may be different. Because the mountings for the tools and theirreciprocating mechanisms are independent of each other, it is obviousthat a variety of conditions may be met without impairing the eiilciencyof the machine.

In Figs. 11 and .12 are shown examples of the tool teeth employed inroughing and finishing. The tooth shown in Fig. 11 is provided withalternate lands and recesses, but the lands are is shown dia atesimultaneously on asingle gear, the roughlng cutter must be set slightlyahead of the finishing cutter in the relative longitudinal move mentbetween a tool and the work, so that it operates on the gear first andis then followed by the finishing cutter. The finishing cutter may beadjusted in either of two ways, viz.: finst, it

may be set at a greater depth than the roughing cutter so that it causesadditional cutting or, second, it may .be set at the same depth as theroughing cutter, in which case it will act to clean up the surface butnot remove metalto a greater depth. 0

In the standard form of gear cutting machine, it is.usual to have acertain down-set at the end of the feeding stroke in each direction,that is, the work gear is fed across the cutter and at the time its feedmovement is reversed there is an .automatic movement of the machine tocause the shafts to come closer together. ,Where the roughing cutter isacting on the work in advance of the finishing cutter, it reaches theend of its stroke first and is automatically down-fed, whereupon itstarts its return stroke while the finishing cutter is still completingits movement in the first direction. In the commercial finishing ofgears with both a roughing and a finishing cutter, it has been foundthat it is possible to completely finish a gear-in four passes, that is,four complete cycles of reciprocation. When working on a gear with aroughing tool only it is usually sufilcient to use only two passes whilethe finishing operation normally requires four passes. When operatingsimultaneously with both a roughing and a finishing tool,'the roughingtool is down-fed at-'the end of each stroke for two 1 passes and at theend of the two passes, no fursubstantially less in width than therecesses. The

finishing tool on the other hand is provided with teeth of the typeshown in Fig. 12 and is similar to those disclosed in the co-pendingapplications referred to hereinbefore, wherein the lands and recessesare substantially the same width. It will thus be seen that in theroughing operation fewer cutting edges and less contact surface arepresented to the work than is the case with the finishing tool. However,the roughing tool provides for greater chip clearance and less surfacecontact so that if desired the tool can be fed to the work 'at adifferent rate than that at which the finishing tool is fed. The primarydifference between the roughing cutter and finishing cutter is that inthe roughing cutter the serrations or recesses are of greater width withrespect, to the intermediate lands while in the finishing cutters therecesses and lands are normally of approxlm 1y equal width. The resultis that the roughiii) ther down-feed is given to the roughing cutter.

0n the other hand, the finishing cutter is given a down-feed at each endof the stroke until four complete passes are finished. It is importantto note that while the cutters remove a certain amount of metal fromeach sideof the gear teeth during the feed movement in one direction,there is a greater amount of cutting on one side of a tooth, namely, thedriving side, but in the return feed movement the opposite sides of theworkteeth receive the greater amount of cutting action.

With the mechanism described herein, there are several ways of operatingthe machine for combined roughing and finishing. For example,

there may be a down-feed at the end of each stroke; or at the end of thestrokes including the down-feed a finishing cutter may continue anotherfinishing cut in one direction, he down-fed slightly, and have a finalreturn stroke; or again, the finishing cutter may continue for anothercycle of reciprocation without any down-feed.

In some circumstances it is desirable to stop the translation of theroughing cutter at the endof each stroke until the finishing cutter hascaught final cycle of reciprocation to complete the fiii iii cutter withits wide recesses will take heavier cuts but will not be as accuratebecause there is less guiding surface for maintaining accurate cutting.

up with it, and then start the return translatign of the roughing cutterfollowed later by the re-I turn stroke of the finishing cutter.

from the work while the finishing cutter ha ishing operation. It may bedesirable to have two roughing cuts, one in each direction, sufficientto properly rough the gear and the re-.

mainder of the finishing action'is accomplished solely by the finishingcutter.

While the machine has so far been described 1 In othg cases, theroughing cutter should be withdrawng withregard to the cutting, it isobvious that the ting. Where the tools employed are lappingtools.satisfactory results are obtained by driving either the work or thetool. When cutting tools areemployed, however, it has been foundprefe'rable to drive the work to obtain uniformity of cut and a betterdistribution of the driving force.

In Fig. 13 a further modification of the invention is shown. Inthis viewtwo axially aligned gears ISA and i613 are each acted upon by a pair oftools. Gear I 6A meshes with cutters l9A apparatus and method, outlinedherein may be used for lapping and burnishing as well as cutluteprofile. In the manufacture of such a gear and 20A, while gear IBB isacted upon by cutters H93 and 2013. The cutters may be any of the typespreviously described, particularly in reference to Figs. 9 and 10. Thetwo gears need not it is normally hobbed to approximate dimen-. sions,as shown by the dotted lines 92, leaving sufficient stock for the finalfinishing operations. It is not commercially feasible tohob .a profilehaving the beveled face 9|, and therefore the connecessarily be formedintegral with the shaft but may be secured thereto by any suitablemeans. In principle, the method of finishing the gears is similar tothat described with reference to that of the other figures of thedrawings. The gears to be'finished may either have spur or helicalteeth. The invention is also applicable to finishing herringbone gearswhich are essentially two adjacent helical gears of opposite hand; Thearrangements of either Fig. 9 or Fig. 13 can be 'used with herringbonegears.

In the several views comprising the drawings, the means for drivingagear is shown as an elec-. trical motor, butany suitable driving means:may be employed. While it is preferred that the shaft carrying theworkpiece be driven'and the tools rotated by their intermeshing engagementwith the gear, it is nevertheless apparent that the motor forreciprocating-the tool carriages may be coupled to the tools when it isdeemed expedient to drive the tools. I

In the previous description, attention was called t to the fact that theinvention has an important use in connection with cluster gears, but itshould be noted that it may also be used for finishing two separategears which are mounted on a single arbor insuch relation respectivecutters.

It is desired to point out that when-a roughas to cooperate with the ingcutter of the type illustrated in Figure. 11 is tour as hobbed'is ofapproximate involute form, thus leaving a greater amount of stock to beremoved in the finishing operation between the tip portion 93 and thebevel portion 9i. .The

. roughing and finishing cutters for producing the conjugate to thebevel portion 9|.

cutter, because 01' its ability to take a heavier bevel 9| are shown inFigure 15, where it will be noted that there is a flaring portion 94which is The roughing cut, is used to reduce the work gearto the toothsize indicated by the dotted lines 9|, and it will be observed that itisnecessary to remove a considerable amount of metalfrom the tip portion93 in order to approximate the final tooth form 9|. The finishing cutteris then employed to re. move the slight amountof metal between thecurves 95 and the finished tooth form 9|. Assuming for example that thedistance between the curve 92 and the curve 95 is approximately .002

. inchQit will be observed that at the point 99- metal by the roughingcutter.

there may be removed as much as .009 inch of The finishing cuttermay-then be usedtto bring the tooth to the final size andthis cut isnormally approximately .0005 inch.

It will be understood that the figures given above are merely by way ofexample to illus-" trate thev respective functions'of the roughing andfinishing gear cutters. It will be clearly ap- .parent, however, thatthere is a distinct advantage in combining the roughing and-finishingused for shaving, it is normal to employ a greater angle between theaxis of the tool and the work than it is when a finishing cutter of thetype shown in Figure 12 is used.

In connection with that feature of myinven tion which relates tothe useof roughing cutters and finishing cutters for the work. it is desired topoint out some of the advantages incident to this combination.- Theroughing cutters with the wider grooves between the land's mounted at agreater crossed axes relationship, will -cormet all of the inaccuraciesin the roughed-out work gear except the involute form. The finishingcutter corrects the involute form and imparts s smoother and bettersurface to thework gear teeth. The roughing cutter. because of itsinherent characteristics, hasaionger'lif'b'efore it is necessary toregrind the same, and even though it does a greater percentage of thework,

it is found that it will stand up better than a finishing cutter if thelatter isused alone. 0n the other hand, where both roughing andfinishingcutters are used, the finishing cutter is reli'eved of some ofthe work which it would normally' do,'*and therefore the life oi. thefinishing cutter is also extended. Thus the combination v of theroughing and finishing cutters effects a" cutters for producing aseveremodification in.a

tooth profile as illustrated in Figure 14.

A modified form of gear finishing machine is shown in Figures 16 to 19.The modified machine differs primarily from the machine shown in Figure1 in that provision is made for recip rocating the work-carrying slidewith respect to the cutters instead of reciprocating the cuttercarryingheads. The modified'machine is substantially the same in generalconstruction as the one previously described in detail except for theprovision for the reciprocation of the work- I carrying slide.

As shown in Figure 1s, a slide in is mounted for horizontalreciprocation ontlie ways ill. The slide ;i99 has a bracket J92extending within the'hollow frame It, for the purpose of supporting thedriving mot0r-l-l'1 The motor l|l drives throughya coupling I99 tli tIll (see Figur ls) on which there is a worm I95. The worm gear-I99meshing with worm I99 is mounted on the shaft I91 journaled in bearingsI99 and m m the frame of the slide m. The shaft both "for the purpose-orrotating the 7th: gear I01 serves to transmit the power; 01f the motor4K and reciproating the slide 100. For rotating 1 the .work gear,suitable changegeaijare proi". I v [F fram II of the machine.

- tallstock I32.

vided in order that the speed of rotation may be predetermined. Asshown, the shaft I01 has a gear IIO thereon meshing with the pinion IIIcarried by the auxiliary shaft H2. The shaft also has a gear H3 whichmeshes with the gear I I4 on the shaft I I5, which latter forms thedriving shaft for the work.

For reciprocating the slide, the shaft I01 is provided with a worm H6which engages the worm gear IIB on a cross shaft II9. On the shaft is abeveled gear I meshing with the beveled gear I23 carried by the shaftI24. .This shaft extends into the enlarged housing I25 at the end of theslide and has secured thereto a gear I26 which meshes with the gear I21on the screw I29 and is suitably mounted in the slide I IIII to take upend thrust. The lead screw I29 engages a nut I30 secured by bolts I3I tothe The slide I90 has adjustablymounted thereon the tailstock I32 whichmay be clamped in position by suitable bolts I33 engaging the T-slotsI34. The tailstock is similar to the one previously described and caries a'center in axial alignment with the dr' i g shaft H5. The workpiece I35 is adapted to e inserted between the driving coupling I36 onthe shaft H5 and the In the machine as described, the rotary cuttingtools are carried by the heads I2I and I22 which are adjustable in thesame manner as described in connection with the machine shown in Figure1, except that the mechanism for reciprocating the cutters is eitherdisconnected or eliminated entirely from thev machine. When the motor III is energized, it causes the work piece I35 to revolve, while thecutters in the heads I2I and I22 are driven by the intermcshing actionof the teeth. At the same time the slide I00 is given a slow feedmovement in the direction of the aXis of the work gear. Suitable limitswitches are provided for reversing the motor II'I after a predeterminedfeed movement which causes the direction of, rotation of the work pieceto be changed and the slide to' be moved axially in the oppositedirection. Theaction of the machine is the same in principle as themachine first described.

What I claim as my invention is: a

1. A machine for finishing gears comprisin a frame. a work sup ortrotatably mounted on said fra e, a plurality of tool supports carried bvsaid frame. means for providing relative recinrocation between the toolsupports and the work support. means for rotating said work support andsaid tool supports. and means automatically operable, in timed relationto said relative reciprocation to feed said tool supportssimultaneously, substantially radially toward said work support.

2. A gear finishing machine of the type dis-- closed comprising a frame,a work support on said frame, a tool hanger adjustable radially towardand'from said work support, a tool carriage reciprocable on said hangerin a plane parallel to the axis of said work support, a motor carried bysaid carriage for reciprocating said carriage, a tool head carried bysaid carriage and adjustable about an axis generally radially disposedto the axis of said work support, a rotary tool support carried by saidtool head, and drive means including a clutch for connecting said shaftI28, the latter being coaxial with the shaft I01. The shaft I28 isprovided with the leadmotor to rotate said tool support in any positionof adjustment of said tool head.

3. 'A gear finishing machine comprising a work carriage slidably mountedfor reciprocation, a work arbor rotatably carried thereby, a motor onsaid carriage, transmission means between said motor and work arbor forrotating said work arbor from said motor, and other transmission meansdriven by said motor for translating said carriage, a plurality of toolarbors. disposed radially of said work arbor and adjustable in feedingrelation radially of said work arbor, and means responsive totranslation of said work carriage for simultaneously feeding said toolarbors radially toward said work arbor.

4. A gear finishing machine comprising a work carriage slidably 'mcuntedfor reciprocation, a work arbor rotatably carried .thereby, a motor onsaid carriage, transmission means between said motor and work arbor forrotating said work. arbor from said motor, and other transmission. meansdriven by said motor for translating said carriage, a plurality of toolarbors disposed radially of said work arbor and adjustable in feedingrelation radially of said work arbor, said tool arbors adapted tosupport gear like finishing tools in mesh at limited crossed axes with agearcar ried by said work arbor, and means responsiveto translation ofsaid work carriage for simultaneously feeding said tool arbors radiallytoward said work arbor,'-substantially at the end of a translation ofsaid work carriage.

5. A gear finishing machine comprising a work carriage slidably mountedfor reciprocation, a work arbor rotatably carried thereby,. a motor onsaid carriage, transmission means between said motor and work arbor forrotating said work arbo'r from said motor, and other transmission meansdriven by said motor for'translating said carriage, a plurality of toolarbors disposed radially of said work arbor and adjustable in feedingrelation radially of said work arbor, and means responsive totranslation of said work carriage for simultaneously feeding said toolarbors radially toward said work arbor, said last means comprising a camdevice for each tool arbor, and

a single motor having driving connection with each of said cam devices.

6. A machine. for finishing gears comprising a frame, a work supportrotatably mounted on 'said frame, a plurality of tool supports carriedby said frame, means for providing relative reciprocation between thetool supports and the simultaneously, substantially radially toward saidwork support.

17. A' machine for finishing gears comprising a frame, a work supportrotatably mounted on said frame, a plurality of tool supports carried bysaid frame, means for providing relative resimultaneously,

.ciprocation between the tool supports and the work support in adirection parallel to the axis of said work supportmeans for rotatingsaid work support and-said tool supports, and means automaticallyoperable in timed relation to said relative reciprocation to feed saidtool supports substantially radially toward said work support, said feedtaking place substantially at the end of a stroke of said relativereciprocation.

3 ROBERT S. DRUMMOND.

